Centrifugal fan.



R. HANGOCL GENTRIFUGAL PAN.

v APPLICATION PILED BEPT.6,1910. 1,031, 180.

Patented July 2, 1912.

3 SHBETSSHEET 1.

INvErn-o RALPH HANCOCK Hrs ATTOR R. HANCOCK.

' GBNTRIPUGAL mi. APPLICATION FILED SEPT. 6, 1910.

Patented July 2, 1912.

3 BHEBTBBHBET 2.

INVENTOR 'RALPH HANcocK BYJZJ 4mf Mrz naar.

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rrnessEs; v NV EEEE I EEEEEEEEEEEEEE California, i Improvements in Centrifugal Fans, of which `so`asto blade in Fig.

ALPH HANCOCK, 0F SAN FRANCISCO, CALIFORNIA.

' CENTRIIUGAI; FAN.

Specification of Letters Patent. Application led September 6, 1910. Serial No.. 580,600.'

To all whom 'it may concern:

Be itxknown that I, RALPH HANCOCK, citizen of Great Britain, residing in the city and county of San Francisco and State of have invented new and `useful the following is a specification. V vMy invention .relates to centrifugal fans and blowersin which the fluid operated on is admitted axially and discharged circumferentially.

The'bbject of the present invention is to provide a simple', practical fan having a maximum efficiency within a wide range of vconditions of operation; to rovide a maximum inlet with the largest lade area practical, and in which the blades are so shaped that in providing a'maximum blade area the area of the inlet is not obstructed. Also to design the runner and the blades therefor provideboth maximum inlet area and maximum blade area, and at the same time prevent. the natural rush of the air to ythe extreme ends of the blade, giving a rea-ter distribution along the surface of the lades.

Another Objectis to so shape the blades that the runner will be more eicient in its work against a greater range .and variation of pressure, whereby the device is adapted to a greater range of commercial requirements than the fans at present in use.

There are other objects and advantages `which will appear hereinafter, having ref- .erene Ito the accompanying drawings, in

Figure 1' is a longitudinal section ofthe invention. Fig. 2 is a cross-section at mght angles to Fig. 1. i Fig. 3 is an enlarged'section ofthe runner. Fig. 44 is a side elevation in section, of a part of the runner shown in Fig. 3. Fig. 5-is an edge view of the 3. Fig. 6 is an`elevational .view of the same. Fig. 7 is a longitudinal .section showing another arrangement of the .blades in the runner.

A represents a suitable casing, here shown vas involuterin form, having an outlet as 2.

The runner comprises two rings 3, suitably spaced apart and connected by the blades 4 and supported by the spokes 5 from the central shaft 6. The runner is preferably open i at both ends to provide the double suction inlets 7, 'the outlet for the air or other fluid outer diameter of the outer ed es ointerstices between the blades into the in-l i volute of the case A.

The invention resides especially in the shape-of the blades 4. In all cases the blades are dee est or widest at their center and 'taper o gradually .toward their ends adjacent to theintake 7, where they are narrowest. In Fig. 4 the blades are substantially V-shapedlin form, widest in the oentral middle plane vof the runner, and nairowest where theyI join'A the rings 3. Also each blade is. given a transverse dish, as shown at 8, Figs. 5 and 6,and theblades do4 not stand exactly radial but rather incline with respect to a radial plane passing through their ends. In other words, the. blades are yfined at an angle to the center so that instead of their being directedtoward the center of the runner. theyv will intercept the air entering the runner in a more efficient way;

Another feature, to be observed is the s'uc cessive arrangement of the 'blades in the runner as shown in Figs. 2 'and 4, in which each succeeding 'blade is of different radial' i depth from its immediate neighbor.. That is,the deepest blades-are those yof largest area, shown 'as connected with s the 4bladesi-shortening in radial epth to each side Iof these dee t blades so that a view of the apexes of t e several blades rprei i sents a scalloped outline, as shown in Figs. 9. and 4. A-t the same time `each blade as viewed end-wise is `approximately .in the saine plane.

The outer edge 9 of each blade 4 -is made' rentrant, ythe purpose of which is to permit of an increase in ther area of the inlet openings 7, and at the same time revide a greater' blade area without a reduction of the i air space within the casing around the-outer periphery of the runner. By extendin the ythe runner farther into the casing an( reducing the outer diameter bf the center of the run- 100- ner a triangular space 10 is obtained, equal in area to the rectangular'space formed if a straight Iblade were used.4 A

Fig. 7 represents a modificati-on of an arrangement of blades in which the same 105 shape of bladeis used as before described, but the gradual lessening and depth of the blades follows 'in successive series, each series of Vblades circumferentially around theV Patented Juiya, 191,2. l

ches 5;.

.glzdra-lwn in bythe runner ybeing through the wheel or run-ner having the longest blade at 1110 one end and the shortest blade at the other end of the series, stepping up immediately that the intake for the entering air into t-hel casing is made large,'and the largest area of blade surface is brought into use without obstructing the area of the inlet; said'area of the inlet it will be observed, being the inside diameter ot' thev rings 3. Also that the blades are so shaped vby being made deepestl in the longitudinal center. of the ruimer thereby oleringthe increased area so obtained to the passage. of the air, preventing tlie natural rush to the extreme ends of the blade, and giving a greater distribution along` the surface of-tlie blade. Also by graduating the depths of successive blades as illustrated in Figs. 2-4 and 7, the runner is made more efficient in its .work

against a greater range of pressure, that is to say, in case of a lower pressure the shal lower blades are lgiven highest eiiiciency, While lin the case of greater pressure the deeper blades are given their highest etticiency. This design means a greater range rof `commercial requirementsthan that obtainedby aiis'at present in use', which have a uniform `depth of blade; Whereas in my i device the runner has a graduated radial depth entirely around its circumfer ice.

This shape of blade gives great rigidity and strength. .1

`Then working as a double inlet fan With intakes on yboth sides the greater blade area tions are `ot a diainetervless than the inlet obtained gives .large-output, and eiiiciency. Furthermore, this large' blade area is obtained Without causing any 'obstruction in the intake. AL large number of blades can be arranged in a greaterfarea .of the runner without crowding. y l

v'lhe peculiar construction of these' blades, lis suchv that the outer ends lie in a circum- -ference Whose diameter is greater than that of the inlet opening, while the central poryopening. The areas of that portion of the fan blades exterior to the diameter ofthe inlet opening are substantially equal to the Vfshaped central spaces between the diametei' of the circumference vof the-inlet open- '55 blade surface is brought into 'use witliout ings and the rentrant angle of ,the blades.

obstructing the inletl area, 'While the deeper space providedby the central depression of the blades, offers lthe largest possible area of air passage.

Having thus described my invention, what I claim andv desire4 to secure by Letters latent, -is

l. The combination in a centrifugal tan,

of casing, having an end inlet and a peripheral outlet, a ruimer coaxial with the inlet, saidrunner consisting oblades Whose outer and inner edges are Vsforined, so that the edge of the blade nearery the aXiso the runnerforms a vsalient angle and the oppo l wsite edge a rentrant angle, the -outeridiameter of said runnerat ,the ends v being greaterthanthe diameter of the inlet iii-the casing, and the suinnf they areas ofthebportions of the blades extending beyondthe diameter of'` the inlet opening equaling the sum of the triangular'reentrant spaces indicated between the blades and said inlet opening diameter. 1 -v Q. In a centrifugal fan, a. casing having an end inlet opening and peripheral discharge, a runner within the casing journaled coaxially with said inlet opening, said runner having V-shaped blades, said blades wider -at their central apexed portions inthe radial direction ofthe blades and narrowest at .their ends, the ends of the blades eX-.

tending beyond the circumference of the in letjopening, and the -suinof the areas of `the portionslof the blades extending beyond the" diameter. fof the inlet opening equaling the sum of the areasot Athe spaces includedbe tween the rentrant angles of the blades and said inlet opening diameter.

an end kinlet opening andra peripheral ,dischaige, a runner within vthe casingyjour- 3. In acentri'ugal fan, a' casing havingA naled coaxially with said inletopening, said ruimer :having V -sliaped blades, said blades wider at their central apexed portions in,"

the radial directionyof thebladesl and nar# rowest at their ends, the ends of the blades.

extendingfbeyond the circumferencek of the inlet opening, and the sinn of tlieareas of the i portions of the blades extending beyond the diameter of the inlet Aopening vequaling the' sum of the areas ofthe spaces included bef tween the rentrant angles of the blades `and said inlet opening diameter, said 1 blades varying in radial depth.

4i. A centrifugal fan ycomprising a casing with an end inlet 'opening anda peripheral discharge, a runner in the casing and coaxial with the inlet, composed of end rings and'V-shaped blades, eachy of wliicliblades is narrowest inthe radial direct-ion at its ende, the vedge of the blade between its ends nearerthe axis of the ruimer forming a .sa-1

lient angle, the opposite edge f oi-niing a reentrant angle, said salient angle being less than the rentrant angle, with the apexes iol of both angles;approximately equidistant from thee'nds of the blade, said apexed portion being the widest partei? the blade, and the blade graduallytapering and 'diiiiiiiislrl ing in width toward its ends, and spokes connecting the blades with the runner shaft.

A centrifugal fan comprising a casing' with an end inlet opening and a peripheral discharge, a runner in -the casing andco axial with the inlet, composed -of end rings and v-Shaped blades, each of which blades lient angle, the opposite edge forming a reentrant angle, said salient angle being less than the rent-rant angle, with the apexes of both angles. approximately equidistant from the ends of the blade, said apexed pori tion being the Widest 'part of the blade, and

the blade gradually tapering and diminishing inwidth towarddts ends, and spokes connecting the blades with the runner shaft, said bladesextending at-an angle with the 15.1'adial planes of the runner.

6. A centrifugal fan comprising a casing with an end inlet opening and a peripheral discharge, a runner in the casing and coaxial with' the inlet, composed of end rings and V'-shaped blades, each of which blades is nari-cwest in the radial direction at its t ends, the edge of the blade between its ends nearer the axis of the runner forming a salient angle, the opposite edge v-forming a i"` rentrant angle, said salient angle being less than the rentrant angle, with the apexes of' both angles approximately equidistant from the ends ofthe blade, said apexed portion being the widest part of the blade, and the blade gradually tapering and diminishing in width toward its ends, and spokes con-l necting the blades with the runner shaft, said' blades dispo-sed in series, the blades of each series of' successively increasing depth. 7. In a centrifugal fan, a casing having van endl inlet opening, a runner journaled .within theca'sing and coaxially with said opening, `and having blades with rentrant outer edges, said blades each having that 40 edge which is nearest the axis of the runner forming a salient angle, the o-pposite edge forming a rentrant angle, said blades wid'` 7 estin their-9 central apexed portions, and

gradually tapering and diminishing in.

Width toward their ends, andthe ends ot' said blades extending beyond the circumference of the inlet opening, and the major portions of saidv blades between their ends lying inside, of al cylindrical surface which is' concentric with the ru-nner axis and concentric with the inlet opening, and of the saine diameter as the inlet opening.

8. In a centrifugal fan, a casing having an end inlet opemng, arunner journaled A within the casing and coaxially with said opening, and having blades with rentrant outer edges, said blades cach having that edge which is nearest the axis of the runner forming a salient angle, the opposite edge toi-ming a rentrant angle, said blades widest in their central apexed portions, and gradually tapering and diminishing in width toward their ends, and the ends ot said blades extending beyond the circun'iference oi' the inlet opening, and the major portions of said blades between their ends lying inside of a cylindrical surface which is concentric with the runner axis and concentric with the inlet opening and of the same diameter as the inlet opening` Said blades disposedinseries, the blades 1n each series varying in radial depth.

9.` In a fan ruimer, a blade narrowest in the radial direction at itsends, they edgeof the blade between its ends nearer theaxis of the runner forming a salient angle, the opposite edgeV forming a rentrant angle, said salient. angle being? less than the rentrant angle, lwith the apexes of both angles approximately equidistant from the ends of the blade. said apexed portion being the 'widest' partofthe blade, and the bladel gradually tapering and Idiminishing in width toward its ends.

10. In a centrifugal fan, a casing with end inlet openings, arunner jourualed within the vcasing and having blades which are narrowest in the radial direction at their ends, each blade between its ends having its edge nearer the axis ot' the runner inthe form of a salient angle and the opposite edge of the blade in the form of a rentrant angle, said salient angle being less than the rentrant angle, the apexes of all the angles in alinement and in the plane'silbstantlally equidistant from the ends of the runner, the blades being widest at their apexed portion and tapering and diminishing gradually Iin width toward their ends, said inlets in the casing being in unobstructed connection through the runner.

l1. ,Ina fan ruimer, a blade having a flat portion, theedge of the blade of the runner nearer the axis ot' the runner t'o'rming a salient angle in outline, and the, opposite edge a rentrant angle in outline so as to form a substantially V-shaped flat blade surface, said salient angle being less than the rc-ntrant angle and the apexes of both in alinement so that the -flat blade surface will be of greater width midway ot its length than at its terminals, the rentrant. angular edge of the fiat portion being curved and said tlat portion being a continuation of said curved portion and tangential thereto.

12. ln a fan runner, a blade having a tlat portieri, the edge of the runner nearer the 'l axis ot' the runner forming. a salient angle in outline and the opposite edge ot which is a rentrant angle in outline so as to forni a substantially V-shaped flat blade surface, said sulientanglc being less than the reentrant angle and the alinement., so that. the at blade surface will be of greater width midway olf its length than' at its terminals. the reiinlrant angular edge ot the l'lat portion being curved. said flat portion being a continuation ot said curved portion and tangentialh thereto, said curved portion extending the :Hwxes oi' both in length of the blade at approximately anl ,eaiiiall radius throughout its length, the curved portion terminating at its 'edges on a line parallel with the flat portion of the blades,

13. ln a eentrifugal vfan, a fan runner comprising a series otl blades, each blade having a. lat portion, the edge of the runner nearer the 'axis or" the runner forming a salient angle in outline and the opposite edge of which is a-rentrant angle in outline, said ysalient angle being less than the rentrant angle,'the apexes of the angles alined, a curved portion on the outer edge of y the iiat portion and in continuation thereof,

said salient angle being less than the relentrant angle, vthe apexes of the angles aimed, a curved portion on the outer edge ot' the iiat portion and in continuation thereof, said curved portion extending through the length of the blade, rings by which the ends ot' the blades are supported, ashat't disposed axially to the rings, a hub Ion the sli'att, spokes connecting the blades l yto the hub, said blades equally spaced and arraiiffed- Within the rings with their flat portion extending parallel with `the axis. ot the shaft, and each blade inclined to the inteiseeting radii.

l5. ln a. centrifugal lian, a fan runner j comprising a vsei-ies of blades, each blade `liavinga flat. portion, tlieedgeot die runner Y 'Genies .oftliis patent nearer the axis fot the runner forming a salient angle in hotline' and the opposite edge ,'oiining a reintraiit angle in outline, said'salient angle being less than the reentrant angle, the 'aiiaexes olf the angles ali'iied, a yeurved portion on the outer'edge of the portion and a continuation there- Washington,

of, said curved portion extending through the length ot the blade, rings by which the ends ot' the blades are supported, a shaft disposed axially to the rings, a. hub on the "shaftand spokes connecting the blades to -the hub, said blades equallyspaced and ai'- edge of the blade in the form of a rentrantangle,- said salient angle being less than the re'entrant angle, the apexes of all the angles in alinenient and in the plane substantially equidistant from the ends of the runner, the blades being Widest at their Iapexed portion and tapering land diminishing gradually in width toward their ends, said inlets in the casing being in unobstructed connection through the runner, said blades arranged in circumferential series with successive blades in each series varying in radial depth.

17. A blade for centrifugal fans, consist-v ing of a plate having its outside and inside edges both in the torin ot an opened-out V, with the central apexed portion of the plate Widest in the radial direction, the plate tapering and diminishing in Width toward the ends, said plate having its edgewhich is rentrant and whichv isA farthest t'iointhe axis of the tan curved while thebody of the' plate is generally flat, said curved portion beinga continuation of -and substantially tangential to the' flat portion.v

In testimony whereof I have hereunto set n iy hand inthe preseneeotftyvo rsubscribing Witnesses. l

RALPH HANCOCIL 'll/litnesses:

CHARLES Il. PENFIELD, l?. E. lVAYNARD.

may be attained for five cents each, by addressing'theticonimssioner of Patents.;

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